Other Income - Net (Schedule Of Other Income - Net) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Income - Net [Abstract]
Market value gains related to deferred compensation trusts	$ 7,933	$ 8,254	$ 287
Interest income	757	513	671
Other expense--net	(25)	(3)
Total other income	$ 8,665	$ 8,764	$ 958